JPS62103139A - Packaging material for retort pouch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a packaging material for retort pouches that is excellent in retort resistance, transparency, and gas barrier properties, has good film performance, and is inexpensive.

(Prior art) Aluminum foil has traditionally been used as a food packaging material that can be retort sterilized and has excellent gas barrier properties. However, the disadvantage was that the contents were not visible from the outside and were expensive.

In addition, as inexpensive food packaging materials that can be retorted and have excellent transparency, there are polyester, polyamide, polyvinylidene chloride, and partially saponified ethylene-vinyl acetate copolymer, and polyester.

Polyamide and polyvinylidene chloride have lower gas barrier properties than aluminum foil, and ethylene
Partially saponified vinyl acetate copolymers have the drawbacks of high humidity and extremely poor water resistance.

(Problems to be Solved by the Invention) The present invention improves the various drawbacks mentioned above, and improves retort resistance,
The present invention provides a packaging material for retort pouches that is excellent in transparency and gas barrier properties, has good film performance, and is inexpensive.

"Structure of the Invention" The present invention provides one or more silicon or silicon oxides on the surface of a plastic film selected from the group consisting of a polyester film, a polyamide film, and a plastic laminate film containing at least one of these. Provide the above dry plating layer,
This packaging material for retort pouches is made by laminating a polyolefin film and a film printed thereon as necessary with a polyurethane adhesive interposed therebetween.

In the present invention, the plastic film is a polyester film or a polyester film.

Alternatively, a plastic laminate film containing at least one layer of these may be used. If you have teeth.

Ethylene-vinyl acetate copolymer saponified film has low water resistance, and polyvinylidene chloride film deteriorates when a dry plating layer is placed on it.
It cannot be used alone as a plastic film in the present invention, but is used as a laminate film with polyester and/or polyamide.

The plastic film used in the present invention is subjected to discharge treatment such as corona discharge treatment and low-temperature plasma treatment, coating with a silane coupling agent, and coating with a brimer.

Those that have been subjected to surface treatment such as sandblasting to improve adhesion to the dry plating layer, those that have been subjected to axial or two-wheel stretching treatment, and those that have been printed on one or both sides. Good too.

In the present invention, the dry plating layer includes:

Transparent glass, titanium oxide, alumina, etc. may also be considered, but in order to obtain high transparency, one or more types of silicon or silicon oxide may be deposited or sputtered, or a composite layer thereof may be used. However, it may be mixed with other dry plating materials or multilayered with other dry plating layers as long as the transparency of the resulting packaging material is not impaired.

There are no particular restrictions on the method of providing a dry plating layer of one or more types of silicon or silicon oxide, and silicon and/or silicon oxide may be deposited or sputtered in vacuum or in an inert gas. how to,
Silicon and/or silicon S excluding silicon dioxide alone
Methods include reactive vapor deposition or reactive sputtering of an oxide to form a layer of silicon oxide or a mixture of silicon oxide and silicon. The silicon oxide may be a mixture of silicon monoxide and silicon dioxide.

A dry plating layer can be provided on either one or both sides of the plastic film.

From the viewpoint of cost and resistance to rubbing, it is preferable to provide it only on the side to which the polyurethane adhesive is applied.

When a dry plating layer is provided on one side of a plastic film, the thickness of the dry plating layer varies depending on the material and thickness of other materials used in the packaging material of the present invention, but from the viewpoint of gas barrier properties and flexibility, the thickness of the dry plating layer is 300 mm. ~6
000 people, especially 400 to 3000 people. 100
Gas barrier properties tend to decrease below 6″0.
If the number exceeds 0.000 people, flexibility tends to decrease and costs tend to increase. After providing the dry plating layer, further discharge treatments such as corona discharge treatment and low-temperature plasma treatment, application of a silane coupling agent, printing, etc. may be performed. Printing is important in terms of heat resistance, adhesion, and resistance to rubbing of printing inks.

Preferably, it is applied on a dry plating layer rather than on a plastic film or a polyolefin film.

In the present invention, as a polyolefin film.

The desired material and thickness can be selected from polyethylene, polypropylene, polybutylene, methylpentene polymer, etc., but it is preferable to use polypropylene from the viewpoint of heat sealability and retort resistance, and from the viewpoint of adhesiveness It is preferable to use a polyolefin film whose surface has been subjected to discharge treatment such as corona discharge treatment or low-temperature plasma treatment. The polyolefin may be a modified product such as a carboxyl-modified polyolefin. Polyolefin films are coated with primers such as organic titanate compounds, polyethyleneimines, and isocyanate compounds.

It may be subjected to surface treatment such as sandblasting, -axis or two-wheel stretching treatment, printing, etc.

In the present invention, it is possible to use a true melt adhesive as the adhesive, but using a hot melt adhesive increases the thickness of the adhesive coating, which is uneconomical, and the high bonding temperature causes thermal deterioration of the film used. This is because film performance tends to deteriorate as a result.

In the present invention, by using a polyurethane adhesive,
It is possible to obtain a packaging material that is inexpensive and free from thermal deterioration of plastic films and polyolefin films. As the polyurethane adhesive, in addition to a two-component curing type, a moisture curing type can also be used.

The polyurethane adhesive may contain additives such as silane coupling agents.

Polyurethane adhesive is usually 2.5-4g/n? (solid content) is applied, and if necessary, the solvent bone is dried and removed. After laminating a plastic film and a polyolefin film at 60 to 80°C via a polyurethane adhesive,
Aging is usually carried out at 30 to 60°C for 2 to 4 days.

A retort pouch can be obtained by heat-sealing the packaging material of the present invention thus obtained, with the polyolefin film side facing inside. The heat sealing temperature varies depending on the material of the polyolefin film, and is about 125 to 220°C when the polyolefin film is made of polypropylene, and about 120 to 175°C when the material is polyethylene.

In the case of polybutylene, a temperature of about 120 to 200°C is suitable.

The retort pouch according to the present invention can be used not only for food, but also for packaging pharmaceuticals and medical instruments, as well as for infusion bags.

(Example) The present invention will be explained below with reference to Examples.

Example 1 Polyester film “Ester E-5” with a thickness of 12 μm
001J (Toyobo Co., Ltd.), silicon monoxide was vacuum-deposited to the thickness shown in Table 1, and the two-component curing polyurethane adhesive "Atocoat AD-90" was applied to the deposited surface.
0J and rR'T-5J (Toyo Morton) were applied and dried to a coating amount (solid content) of 3.5 g/rd.
A 60 μm thick polypropylene film “Shorex Aroma-AJ (Showa Denko)” was laminated on the coated surface at 70°C and further aged at 40°C for 3 days to obtain a packaging material. Oxygen permeability of the resulting packaging material and moisture permeability were as shown in Table 1.

(Left below) *Unit: mβ/M, 24 hours, 1 atm, 25℃**J
IS Z0208 cup method (40℃, 90%R) I)
, unit: g/a・24 hours Among the obtained packaging materials, -silicon oxide vapor deposition film thickness is 700
Heat-seal at 180°C with the polypropylene film side inside using a plastic bag with internal dimensions 12cm x 1.
A 6 am retort pouch was obtained.

Curry food "Bon Curry" (
Otsuka Foods) 100g was filled and retorted at 125°C for 30 minutes. The oxygen permeability of the packaging material after retort treatment is 1.3 nl/r+f, 24 hours, 1 atm, 25°C,
The moisture permeability was 1.2 g/rd for 24 hours. Furthermore, there was no change in the contents even after the retort treatment and storage at 66°C for 30 days.

Comparative Example 1 "Instead of Ester E-5 0 0 1J. Thickness 12μ
m polyvinylidene chloride coated polyester film
Using Ester KE-8002J (Toyobo).

The packaging material obtained in the same manner as in Example 1 except that vacuum deposition was not performed had an oxygen permeability of 7 ml/rd, 24 hours, 1 atm, and 25°C, and a moisture permeability of 3 g/rrl, 2.
It was 4 hours.

Using the obtained packaging material, a J retort pouch was made in the same manner as in Example 1 and subjected to retort treatment. Is the oxygen permeability of the packaging material after retort treatment 10 nl/I? ? - 24 hours, 1 atm, 25°C, moisture permeability was 5 g/rrf, 24 hours. In addition, after retort processing, the samples were stored at 66°C for 15 days. The contents had deteriorated and the flavor had been significantly impaired.

Comparative Example 2 [Instead of ester KE-8 0 0 2J, thickness 15
The oxygen permeability of the packaging material obtained in the same manner as in Comparative Example 1 except that μm of partially saponified ethylene-vinyl acetate copolymer FI)LMUrEVAL EF-XLJ (Kuraray) was used was lz1/m・24 Time, 1 atm, 25℃, moisture permeability 6g/n?・It was 24 hours.

The same procedure as in Example 1 was carried out using the obtained packaging material.

A retort pouch was made and retort processing was performed. The oxygen permeability of the packaging material after retort treatment is 70mj! /nf・24
Hours: 1 atm, 25℃, moisture permeability: 7 g/rrl, 24
It was time. In addition, when stored at 66° C. for 15 days after retort treatment, the contents had deteriorated and the flavor was significantly impaired.

Example 2 A 15 μm thick polyamide film “Harden N1102J (Toyobo)” was used instead of Ester E-5001J, except that silicon monoxide was vacuum-deposited on one side to a thickness of 700 μm. The oxygen permeability of the packaging material obtained in the same manner as in Example 1 was 1+++1/rrr・2
The temperature was 4 hours at 1 atm and 25°C, and the moisture permeability was 1 g/M for 24 hours.

The same procedure as in Example 1 was carried out using the obtained packaging material.

We performed retort processing to make retort pouches. The oxygen permeability of the packaging material after retort treatment is 1.8mj! //・24
Time: 1 atm, 25℃, moisture permeability: 1.5g/rrr・2
It was 4 hours. In addition, after retort treatment, 15
There was no change in the contents even after storage for several days.

Comparative Example 3 Oxygen permeation of a packaging material obtained in the same manner as in Comparative Example 1 except that a 15 μm thick polyvinylidene chloride coated polyamide film [Harden KN8002J (Toyobo) was used instead of Ester KE-8002J. rate is gt
*l/rd, 24 hours, 1 atm, 25℃.

The moisture permeability was 5 g/rd for 24 hours.

The same procedure as in Example 1 was carried out using the obtained packaging material.

A retort pouch was made and retort processing was performed. The oxygen permeability of the packaging material after retort treatment was 15 m//m for 24 hours at 1 atm and 25°C, and the moisture permeability was 6 g/rrr for 24 hours. Furthermore, after being stored in a retort for 15 days at 66°C, the contents deteriorated.

The flavor was also significantly impaired.

Example 3 The oxygen permeability of a packaging material obtained in the same manner as in Example 1 except that silicon dioxide was sputtered to a thickness of 600 mm instead of vacuum deposition was IIIN/d・24 hours・1 The atmospheric pressure was 25°C, and the moisture permeability was 1 g/rd for 24 hours.

The same procedure as in Example 1 was carried out using the obtained packaging material.

A retort pouch was made and retort processing was performed. The oxygen permeability of the packaging material after retort treatment is 1.2n+4'/rrf
・24 hours・1 atm・25℃, i3 humidity 1.1g/r
It was 24 hours. In addition, after retort processing, 66
There was no change in the contents even after storage at ℃ for 15 days.

Example 4 The oxygen permeability of a packaging material obtained in the same manner as in Example 1 was 1 mff/n ( - 24 hours, 1 atm, 25°C, moisture permeability was 0.9 g/nf, 24 hours.

The same procedure as in Example 1 was carried out using the obtained packaging material.

A retort pouch was made and retort processing was performed. The oxygen permeability of the packaging material after retort treatment is 1.5++l/rrr・
24 hours, 1 atm, 25℃, moisture permeability 1.5 g/
rd・24 hours. In addition, after retort processing, 66
There was no change in the contents even after storage at ℃ for 15 days.

Example 5 Polyethylene terephthalate film with a thickness of 12 μm
Silicon monoxide was vacuum-deposited on one side of Ester E-5006J (Toyobo Co., Ltd.) to a thickness of 700 μm, and a 60 μm thick polypropylene film “Shorex Aroma-A” ( A 50 μm thick polyamide film “Harden N1102J (Toyobo IJl)” was laminated on the non-evaporated surface in the same manner as in Example 1, and further aged at 40° C. for 3 days to obtain a packaging material.

Using the obtained packaging material, the same procedure as in Example (2) was carried out.

A retort pouch was made and filled with 100 g of a 10% amino acid preparation "Powerful New Amine" (Toyo Jozo Co., Ltd.), and sterilized at 121° C. for 10 minutes. The oxygen permeability of the packaging material after sterilization is 1.2mj! /d, 24 hours, 1 atm, 25°C, and moisture permeability was 1.1 g/d, 24 hours. Furthermore, after sterilization, there was no change in the contents even after storage at 4°C for 120 days.

"Effects of the Invention" According to the present invention, it has become possible to obtain a packaging material for retort pouches that is excellent in transparency, gas barrier properties, and retort resistance, has good film performance, and is inexpensive.

Claims (1)

[Claims] 1. One or two types of silicon or silicon oxide on the surface of a plastic film selected from the group consisting of a polyester film, a polyamide film, and a plastic laminate film containing at least one layer of these. A packaging material for retort pouches comprising a film provided with the above dry plating layer and printed thereon as required, and a polyolefin film laminated via a polyurethane adhesive. 2. The packaging material for retort pouches according to claim 1, wherein the polyolefin film is a polyolefin film subjected to electrical discharge treatment.